RESUMO
A fungal endophyte isolated from the leaves of the allelopathic plant Amaranthus viridis of the family Amaranthaceae was identified as Chaetomium globosum through molecular means using internal transcribed spacer (ITS) region of rDNA gene. This is the first report of the isolation of C. globosum from Amaranthaceae. Chromatographic separation of the EtOAc extract of the fungal fermentation in potato dextrose broth yielded two known chlorine-containing azaphilone derivatives, chaetomugilin D (1) and chaetomugilin J (2). Compounds 1 and 2 were found to show phytotoxic activity in the lettuce (Lactuca sativa) seed germination bioassay. The IC50 values of 1 and 2 for root growth inhibition were 24.2 and 22.6 ppm, respectively, while IC50 values for shoot growth inhibition were 27.8 and 21.9 ppm, respectively. Phytotoxic activities of the chaetomugilin group of compounds have been reported for the first time, although their antifungal, antimicrobial and cytotoxic activities are known.
RESUMO
Tomato Yellow Leaf Curl Virus (TYLCV) is an important plant virus on one of the economically most important vegetable crops; tomato (Lycopersicon esculentum Mill.). This had not been molecularly detected before, in Sri Lanka. TYLCV-GN-SL was isolated from apparently infected tomato plants using modified Cetyltrimethyl Ammonium Bromide (CTAB) method in Gannoruwa. Associated Begomoviruses were detected using Deng 541/Deng 540 and AV 494/AC 1048 primer pairs. TYLCV was detected for the first time in tomato in Sri Lanka using P1V/P4C, TYLCV specific primer pair. Nucleotide sequence of coat protein of isolated TYLCV-GN-SL proved that the Indian strain of ToLC virus was closely related to Tomato Leaf Curl Sri Lanka Virus (TLCV-SL: 97%) and Tomato leaf curl Geminivirus (TLCGV: 93%) through direct sequencing data. TLCV-SL was confirmed as TYLCV isolate. TYLCV was molecularly detected from major tomato growing districts like Badulla, Nuwara-Eliya, Kandy and Matale in Sri Lanka.